This is one of UNESCO’s transboundary bilateral natural heritage sites and is made up of ten separate beech forests, four of which are in Slovakia and six in Ukraine, all of which enjoy the highest (fifth) level of forest protection.
International committee of UNESCO organization inscribed Slovak-Ukrainian beech primeval forests among 166 localities of the world natural hreitage. Carpathian beech primeval forests are exceptional because they create a chain of "islands" of the original natural forest, which has grown here for thousands of years. This is a rare case of sample of primeval forests in the relatively small area. Hundred years old firs, beeches, maples and great quantity of dead wood, which represents breeding ground for thousands of mushrooms and shelter for precious fledglings such as collared flycatcher, Ural owl or while-backed woodpecker are to be found here.
The National Nature Reservations of Stužica, Havešová and Rožok form part of Poloniny National Park, while the Nature Reservation of Kyjovský pralesis in the Vihorlat Protected Landscape Area. In what is the largest concentration of primeval forests in Slovakia, visitors can find impressive examples of fir, beech and maple trees of various ages and size. Such trees are of considerable scientific value, and are used for both research and educational purposes.